<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="./vue.js"></script>
</head>
<body>
<script>
    const obj = {
        bookName:"钢铁是怎样炼成的"
    }
    const historyArr = [obj.bookName];
    let _bookName = obj.bookName;
    Object.defineProperty(obj,"bookName",{
        get(){
            return _bookName;
        },
        set(v){
            historyArr.push(v);
            _bookName = "《"+v+"》"
        }
    });
    obj.bookName = "天龙八部";
    obj.bookName = "射雕英雄传";
    obj.bookName = "水浒传";
    console.log(obj.bookName);// ?
    console.log(historyArr)
</script>
</body>
</html>